Following the spring break migration pattern of college students everywhere, a group of Massachusetts students headed south this week -- but not all the way to the beaches of Florida. Instead, the students stopped in Baltimore and spent their vacations volunteering as guest teachers at 10 city schools.

Eleven students from the Massachusetts Institute of Technology, part of a group called MIT Alternative Spring Break, conducted math and science lessons at Baltimore elementary, middle and high schools. The program was facilitated by Teach for America, which recruits recent college graduates to become teachers in needy areas across the country.

'Good for both sides'

"It's good for both sides," said Elizabeth Turner, principal of Tench Tilghman Elementary School, which had two student teachers. "It gives youngsters some experience with career choices and real world experiences. It gives them a sense of what the professional scientist does."

The professional scientist sometimes does some yucky things, pupils at Tench Tilghman agreed. In an experiment created by MIT junior Jeremy Lueck, a computer science major, and sophomore Jessica Wang, a biology major, the Tench Tilghman pupils tasted sugar, lemon, coffee and salt to find out which parts of their tongues were sensitive to certain flavors.

"The coffee was nasty," said Daryl Blow, 10. His classmates agreed: Most raced to the classroom's sink and made mock gagging noises. However, there was some consolation. "The sugar was good," Daryl said.

Math lessons were a bit less eventful. Lueck jotted columns of numbers on the blackboard and asked volunteers to identify the mean (average) and mode (most frequently appearing) numbers. Pencils scribbled across three-ring-binder paper, and a dozen wiggling arms shot into the air. Even the little boy who was sprawled sideways in his chair with his head dangling upside-down looked interested.

"They love it," said fifth-grade teacher Maura McGrail, 25. "It's always fun for them to have young people in who are really enthusiastic."

Lueck and Wang said they were pleasantly surprised by their two days at Tench Tilghman and their two days at Mergenthaler Vocational Technical High School.

'Kids are eager'

"I went in thinking it would be a lot worse than it was," said Lueck, an Iowa native who was quickly anointed "Mr. Jeremy" by the fifth-graders. "It looked like a tough high school. But the kids are eager to learn in both places."

Other MIT students were guest teachers this week at schools in Washington and in San Juan and Culebra, Puerto Rico.

Thursday, Lueck and Wang spent the afternoon explaining to Bill Pittard's fourth-grade class how the brain works. While fielding questions such as "How come your brain doesn't jump?" the two patiently explained how parts of the brain have special jobs. Then, they bravely opened the floor to questions.

"Is part of your body made of water?" wondered one child. Without missing a beat, the MIT pair responded: "70 percent."

Positive reaction

The pupils reacted so positively to the guest teachers that Turner said she is thinking about recruiting others from schools such as Morgan State University to visit her classrooms.

That idea probably would be greeted warmly by the under-4-foot crowd. Summing up the benefits of the MIT visitors, 10-year-old Racquel Watson said, "They taught us how to have fun in school."

Daryl, who now plans to become a scientist along with a movie star, a wrestler and a professional football player, issued a swift correction.